1. Field of the Invention
Aspects of the present invention relate to a barrier and a battery module having the barrier, and, more particularly, to an improved barrier structure interposed between unit batteries and a battery module having an improved barrier structure interposed between unit batteries, by which a manufacturing process may be simplified and an effect of a manufacturing defect may be minimized.
2. Description of the Related Art
A battery module includes a few or several tens of connected rechargeable batteries. The rechargeable battery may be repeatedly charged and discharged because chemical and electrical energy conversion thereof is reversible. While a low capacity battery is used in portable miniaturized electronic devices (e.g., a mobile phone, a laptop computer, and/or a camcorder), a large capacity battery is widely used as a power supply to drive motors of movable electric apparatuses such as a hybrid electric vehicle.
The rechargeable battery may have a variety of shapes and may be cylindrical or rectangular. The large capacity rechargeable battery is constructed by connecting a plurality of unit batteries in series in order to allow the rechargeable battery to be used in large power consuming apparatuses such as the hybrid electric vehicle. As is described above, a single large capacity rechargeable battery (hereinafter, referred to as a battery module) typically includes a plurality of rechargeable batteries (hereinafter, referred to as unit batteries for simplicity of description) connected in series.
Each unit battery includes an electrode assembly having positive and negative electrode plates and a separator interposed therebetween, a casing having a space defined therein to store the electrode assembly, a cap assembly combined with the casing to seal the casing, and positive and negative terminals that protrude from the cap assembly and which are electrically connected with the positive and negative electrode plates of the electrode assembly.
A single battery module is constructed by arranging a plurality of unit batteries along a single line and by connecting positive and negative terminals of neighboring unit batteries to each other using a conductor with engagement tools such as bolts and nuts.
As is described above, since a single battery module is constructed by connecting a few or several tens of unit batteries to each other in series, heat generated from each unit battery should be appropriately discharged. Such a heat sink function is particularly important for a rechargeable battery used in a hybrid electric vehicle.
When the heat is not appropriately sunken, the heat generated from each unit battery may cause an abnormally high temperature in the battery module, and may eventually cause the battery module to malfunction.
Accordingly, when a plurality of unit batteries are used to constitute a battery module, a barrier is provided between the unit batteries to define a space to allow for a circulation of a cooling medium between the unit batteries and to prevent a structural deformation of the unit batteries.
Recently, such a barrier has been constructed by combining a plurality of panels having a plurality of protrusions on each surface of each panel in order to allow for a circulation of a cooling medium and to obtain a sufficient structural integrity.
The aforementioned barrier structure may have some problems, however, with a bonding failure during a process of bonding the pair of panels to provide a single barrier. This bonding failure is generated because appropriately adjusting positions of the pair of panels is difficult. Accordingly, a welding failure between the pair of panels may occur as the positions of the protrusions of the panels deviate from one another.
As a result of the structural failure in the barrier, the cooling medium may be inappropriately circulated, a heat sink characteristic of the battery module may be degraded, the structural integrity of the barrier may be degraded, and the battery lifetime may also be reduced. In addition, since accurately adjusting positions between the barrier and the unit battery in a conventional battery structure is difficult, an assembling failure may also occur.